The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 07-31-2005, 12:32 PM   #1
Chugger
Registered User
 
Join Date: Nov 2004
Posts: 18
Will a 6in rod work with a stock stroke 350?

Hello,
I found a great deal on a set of eagle 6in rods but i dont want a stroker i already have a forged 350 crank and a stock 350 block. What will i need to make these 6in rods work in this block, different pistons, machine work or notching the block?
let em know asap
thanks
chris
Chugger is offline   Reply With Quote
Old 07-31-2005, 03:51 PM   #2
tkeduk8r
Senior Member
 
tkeduk8r's Avatar
 
Join Date: Apr 2001
Location: Alexandria, MN
Posts: 1,462
the crank makes the bigger stroke, not the rods... the displacemt of you motor will actually be the same, well that is until your pistons try to knock your head out through the hood ... i would let the 6 inch rods go to someone else and spend the $$$$ on pther speed parts to make that 350 scream, and built right you can out RPM and fly by a 383... just my 2 cents...
--Mike
__________________
63 C20 2WD, 230/SM420/4.11 73K
68 C30 dump truck, 327,SM425,4.56 66K original
68 C10 2WD SWB Stepper, 250/3-tree/3.73 66K.... Wifes
68 Buick Skylark Custom Conv., 350/TH400/2.56 In our family since '79
69 GMC 1500 SWB 2WD, 350/TH350/3.73 posi...
70 K10 SWB 4X4 4-sp,ps, pb, tilt, buckets, console, sliding back window (Need AC parts) WIP
72 Chevy K20 4x4 350/350/205/4.56 donor
72 Vette 350/M21/3.70 posi, triple black and super fast
84 Olds Cutlass Brougham 350/2004r/4.11 was Dad's
tkeduk8r is offline   Reply With Quote
Old 07-31-2005, 04:02 PM   #3
GenIIIShorty
JUNK COLLECTOR!!!!!
 
GenIIIShorty's Avatar
 
Join Date: Jan 2005
Location: Spokane, WA
Posts: 514
yes, you can put 6 inch rods in a 350. you need to make sure that you buy 350 pistons for a 6" rod. this will give you more torque over a 350 that is exactly the same with stock rods, but it also increases your rotating mass, so your rpm max will drop a little bit. other than the different pistons, you can slap those 6" rods right in.
__________________
baby
The dark side! 2000 XLT PSD F-250 4x4! Offroad package
1970 C10 Short-step soon to be short fleet, maybe? Corvette in truck's clothing in work! Corvette IFS, IRS, TPI and Doug Nash 4+3
GenIIIShorty is offline   Reply With Quote
Old 07-31-2005, 04:05 PM   #4
tkeduk8r
Senior Member
 
tkeduk8r's Avatar
 
Join Date: Apr 2001
Location: Alexandria, MN
Posts: 1,462
yeah genIII is right about the different pistons you can use... just had to chime back in ...
--Mike
__________________
63 C20 2WD, 230/SM420/4.11 73K
68 C30 dump truck, 327,SM425,4.56 66K original
68 C10 2WD SWB Stepper, 250/3-tree/3.73 66K.... Wifes
68 Buick Skylark Custom Conv., 350/TH400/2.56 In our family since '79
69 GMC 1500 SWB 2WD, 350/TH350/3.73 posi...
70 K10 SWB 4X4 4-sp,ps, pb, tilt, buckets, console, sliding back window (Need AC parts) WIP
72 Chevy K20 4x4 350/350/205/4.56 donor
72 Vette 350/M21/3.70 posi, triple black and super fast
84 Olds Cutlass Brougham 350/2004r/4.11 was Dad's
tkeduk8r is offline   Reply With Quote
Old 07-31-2005, 06:03 PM   #5
LONGHAIR
just can't cover up my redneck
 
Join Date: May 2004
Location: Columbus OH
Posts: 11,414
I wouldn't hold my breath waitning to "feel" a performance difference...but from a strength/reliability stand-point, you can't go wrong with this. The longer rods are easier on the cylinder walls, bearings and even wrist pins. Nothing wrong with the 5.7s, but if you can get a "deal" that won't cost much more than rebuilding the stockers, why not?
LONGHAIR is offline   Reply With Quote
Old 07-31-2005, 09:50 PM   #6
bigjimzlll
Senior Member
 
bigjimzlll's Avatar
 
Join Date: Dec 2001
Location: Redding,CA...USA
Posts: 4,736
Quote:
Originally Posted by GenIIIShorty
yes, you can put 6 inch rods in a 350. you need to make sure that you buy 350 pistons for a 6" rod. this will give you more torque over a 350 that is exactly the same with stock rods, but it also increases your rotating mass, so your rpm max will drop a little bit. other than the different pistons, you can slap those 6" rods right in.
how does it increase the rotating mass? Sure the rod may weigh a few grams more..but the piston for a 6" rod is a lot lighter...lighter in the right end of the stroke

oh for a deal..check this out
http://www.cnc-motorsports.com/product.asp?ProdID=4187
__________________
It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications

click the clicky to join the site....
http://67-72chevytrucks.com/vboard/payments.php


67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44
Anderson,CA

Last edited by bigjimzlll; 07-31-2005 at 10:07 PM.
bigjimzlll is offline   Reply With Quote
Old 07-31-2005, 08:27 PM   #7
purple gas
Registered User
 
Join Date: Oct 2004
Location: saskatoon, planet earth
Posts: 694
I don't know squat about rod lengths & stuff. But I do know about " deals " . I love deals, but a lot of the deals I've got over the years often meant more frustration and sometimes more money in the long run for something that wasn't exactly what I wanted. A wise man once said " A bargain is something you don't need at a price you can't refuse". Good luck with your motor.
__________________
I got a bench seat baby, you don't have to sit over there.
purple gas is offline   Reply With Quote
Old 07-31-2005, 09:36 PM   #8
GlennBrittain
Senior Member
 
Join Date: Jun 2003
Location: Panola County Texas
Posts: 401
These are two sites I found on searching rod length on the net, good info



http://www.victorylibrary.com/mopar/rod-tech-c.htm

http://www.truckpulls.com/Tech%20Fil...20Prepping.htm
GlennBrittain is offline   Reply With Quote
Old 08-01-2005, 02:31 PM   #9
Chugger
Registered User
 
Join Date: Nov 2004
Posts: 18
i did some more research and found a set of 5.7in h-beams for fairly cheap. Gonna try to build the motor for spray. I spun 2 rod bearings and 1 main the pther day. Gonna get a forged crank, h-beam rods and some forged pistons. Not sure on the compression ratio yet thinkin high 9's to mid 10's any info on that would be greatful?
Also it has a 125 shot now it will prob end up with a 200-250 shot not sure yet.
gonna get a set of aluminum double humps or the new cast heads from jegs or summit not really sure on the heads i might even go with vortec heads.
any info will be greatly appreciated
thanks
chris
Chugger is offline   Reply With Quote
Old 08-01-2005, 02:52 PM   #10
panhandler62
Java Mechanic
 
panhandler62's Avatar
 
Join Date: Jun 2005
Location: Martinsburg, WV
Posts: 6,764
Longer connecting rods provide for a greater moment arm which results in greater tourqe. There is not a huge difference in mass (and that will probably be compensated for by the new pistons anyway) but like any lever system, you can use a short moment arm to gain velocity or a long moment arm to gain tourque. A connecting rod may not look much like a lever but that is exactly what it (in combination with the crank journel) is.

There is a set amount of energy released in any given engine. Making a mechanical change such as this does not change the net energy release, it changes how it is transfered from the reciprocating action to the rotational action.
__________________
Keith
11 Lincoln MKT -- Momma's wagon
13 G37xS -- middle age crazy car
68 C20 Fleetside -- RIP
Decorating the whole town up at a cost of $27 ....
panhandler62 is offline   Reply With Quote
Old 08-01-2005, 11:11 PM   #11
ed455
Captain Ed
 
Join Date: Jul 2003
Location: Port Charlotte, FL
Posts: 1,241
Long rods can drastically lower rotating mass. Generally the shorter the compressed height of the piston the lighter the piston will be. Since the piston is out at the end of the rod is is the most effective place to lose rotating weight. Think about a rod/piston like a hammer, a light handle with a heavy head takes a lot of work to swing but is very destructive. A slightly heavier handle with a lighter head is a lot easier to swing and is less destructive. In an engine, less destructive is GOOD.
ed455 is offline   Reply With Quote
Old 08-02-2005, 02:37 AM   #12
Autometer
Registered User
 
Autometer's Avatar
 
Join Date: Apr 2004
Location: Houston.
Posts: 75
You will have to get the block notched. Most machine shops will have a template so they don't have to notched to fit.
__________________
'05 Silverado
'02 Avalanche
'85 C10
'71 C10
'51 3100
Autometer is offline   Reply With Quote
Old 08-02-2005, 09:43 AM   #13
Green Machine
Senior Member
 
Green Machine's Avatar
 
Join Date: Jul 2004
Location: Estherville, Iowa
Posts: 3,371
Block should not have to be notched just for longer rods. If stroking, then yes, but you are using 3.48 stroke.
__________________
1968 C10 307 3spd Long Fleet ------ http://67-72chevytrucks.com/vboard/s...d.php?t=201103
1970 C10 305 Super T10 Long Fleet --- http://67-72chevytrucks.com/vboard/s...d.php?t=202285
1971 C20 383 TH350 Dana Posi ----- http://67-72chevytrucks.com/vboard/s...d.php?t=206894
2001 GMC Sierra 1500 C3 6.0
Green Machine is offline   Reply With Quote
Old 08-02-2005, 09:56 AM   #14
Chugger
Registered User
 
Join Date: Nov 2004
Posts: 18
Just using the stock stroke but am getting a forged crank. I am looking at sppd pro forged pistons but cant decide on the comp to get? Again this motor will be bottle fed on the track and maybe every now and then on the street as well just depends on the victim. Also i am torn to decide what bearings i want clevite or sealed power i have heard great things about both but need someone with firsthand experience with it
thanks
chris
Chugger is offline   Reply With Quote
Old 08-02-2005, 10:32 AM   #15
ed455
Captain Ed
 
Join Date: Jul 2003
Location: Port Charlotte, FL
Posts: 1,241
On a sbc 400 some notching needs to happen when using H beam rods, but for the 3.48 stroke, I can't imagine it would be necessary.
ed455 is offline   Reply With Quote
Old 08-02-2005, 10:18 PM   #16
Autometer
Registered User
 
Autometer's Avatar
 
Join Date: Apr 2004
Location: Houston.
Posts: 75
My Malibu block is notched. It's stock stroke with the Eagle h-beam 6 inch. With the longer rod, the side does come closer to the block. The machine shop used the template and spent 5 minutes to take care of any posibilities of the rod coming too close. I guess to be on the safe side.
__________________
'05 Silverado
'02 Avalanche
'85 C10
'71 C10
'51 3100

Last edited by Autometer; 08-02-2005 at 10:19 PM.
Autometer is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 01:18 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com